<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta name="keywords" content="HTML CSS Javascript">
    <meta name="description" content="描述信息，网页的主要内容">
    <meta name="author" content="someone">
    <!-- <meta http-equiv="Refresh" content="60">  自动刷新  -->
    <meta http-equiv="X-UA-Compatible" content="ie=edge"> <!-- 只有IE浏览器能识别，用于何种文档模式 IE8/IE9 -->
    <script type="text/Javascript">
        // console.log('script tag from js.html')
        // console.log('undefined === undefined', undefined === undefined)
        // console.log('null === null', null === null)
        // console.log('NaN === NaN', NaN === NaN)
        // console.log('"" === ""', "" === "")
        let myName = "李雷"
    </script>
    <script type="text/Javascript">
        console.log('my name is ' + myName)
    </script>
    <script src="js.js"></script>
    <title>js基础</title>
</head>
<body>
    <h1>JS基础</h1>
    <div class="parent" data-name="name-parent" data-age="60" >
        text of parent div
        <div class="child" id="child" data-name="name-child" data-age="28" >
            text of child
            <span class="grandchildren" id="grandchildren" data-name="name-grandchildren" data-age="1" > text of grandchildren </span>
        </div>
    </div>

    <script type="text/Javascript">
        // console.log('script at bottom of body')
    </script>
</body>
</html>